This invention concerns a breathing air unit. More particularly, the invention relates to a breathing air unit comprising a motor for driving a compressor, wherein compressed air is conducted through a first heat exchanger cooled by cooling air from the compressor.
Relatively strict authority requirements have been stipulated with respect to the quality of compressed air to be used as breathing air. With oil as a lubricant in a compressor chamber and as a coolant for other mechanical components in a compressor, there will always be a risk of getting oil vapour into the compressed air. The air from compressors of this type is therefore unsuitable as breathing air if not subjected to extensive filtering.
According to prior art, so-called oil-free compressors, normally in the form of piston compressors and certain screw compressors, are used for delivering breathing air. The oil-free compressor may form a part of a unit for delivering breathing air. Units of this is type are oftentimes of such a size that they resemble stationary installations.
During work on large constructions with significant distances involved, a need for relatively long pipe- and hose connections arises, which is labour-intensive and must be viewed in context of surrounding work with respect to the danger of breaks in the hose connections. Frequently these hose connections cause condensation and bacterial problems in the breathing air, hence result in an uncertain supply of breathing air to the user.
Moreover, examples of prior art within the area of breathing air units may be found in DE 4344353 A1 and JP 8010331 A.
DE 4344353 A1 discloses a portable breathing air unit, wherein the breathing air is cooled by means of a single heat exchanger. This heat exchanger is not cooled by means of the cooling fan of the motor or the cooling fan of the compressor.
JP 8010331 A concerns a breathing apparatus for medical use, wherein a scroll compressor is used in the breathing apparatus.